Laparoscopic, thoracoscopic, arthroscopic, and other endoscopic procedures are well-known surgical techniques that reduce patient recovery time due to minimal tissue damage. Generally, these surgical techniques rely upon the formation of one or more puncture wounds through which a body cavity, such as the peritoneal or the thoracic cavity, can be accessed. In laparoscopic surgery, once the peritoneal cavity has been entered, the same is insufflated with carbon dioxide gas, typically to a pressure of approximately 15 mm-20 mmHg, followed by the introduction of an endoscopic port with inserted trocar, which may either be bladed or blunt.
Most surgeons initially enter the peritoneal cavity using a Veress needle which is pushed blindly through the patient's fascia and peritoneum. The peritoneal cavity is then insufflated followed by the introduction of the laparoscopic port with inserted blunt or bladed trocar, which is also pushed blindly into the peritoneal cavity. Once positioned therein, the inner sheath of the trocar is removed and a laparoscope is introduced through the port to thus provide visualization within the cavity, see for example (“Comparison of direct insertion of disposable and standard reusable laparoscopic trocars and previous Pneumoperitoneum with Veress needle,” Nezhat F. et. al. Obstetrics & Gynecology 78(1), (1991)).
The problem with such procedures, however, is the fact that the body cavity is entered blindly on two separate occasions: first, through the introduction of the Veress needle; and second, through the introduction of the laparoscopic port with inserted trocar, which can and on occasion does injure abdominal organs and major blood vessels.
To the extent laparoscopic surgery is performed upon a patient that has previously undergone an abdominal operation, the preferred surgical practice is to enter the peritoneal cavity under direct vision. In this regard, it is known that when a patient has undergone previous abdominal surgery, the abdominal contents can become adherent to the abdominal wall, making blind placement of a Veress needle and then blind placement of the port with inserted trocar a much more risky technique.
In light of such potential complications that can arise via entry into the peritoneal cavity during laparoscopic surgery, attempts have been made to provide means for safely entering into a body cavity utilizing direct visualization.
Notable Patents Describing Optical Trocars:
In light of such potential complications that can arise via entry into the peritoneal cavity during laparoscopic surgery, attempts have been made to provide means for safely entering into a body cavity utilizing direct visualization. Exemplary of such devices are those disclosed in U.S. Pat. No. 5,441,041, which utilizes a blade moveable between a non-deployed position and a deployed position to thus allow dissection under visualization of an endoscope.
A similar device attempting to provide direct visualization during entry into a body cavity is shown in U.S. Pat. No. 5,569,291. Such reference discloses a device for forming an entry into a body cavity performed under direct visualization of an endoscope. The dissecting portion of the device consists of a clear plastic conical tip with elevated dissecting blades that help advance it into the tissue via a twisting motion. The conical tip, however, is advanced bluntly into the tissue before the same can be identified and, as a consequence, incision of the tissue is performed without prior visualization. In fact, inadvertent entry into an organ cannot be avoided via use of such device, and it is only after the organ is entered, and hence damaged, that such matter can be appraised. Moreover, the use of clear plastic has substandard optical visualization due to optical properties inherent in such material, coupled with the conical shape, such that advancement of the tip fails to provide a clear visualization as the same is advanced through tissue.
Other devices that are similar in nature include U.S. Pat. Nos. 5,720,761; 5,551,947; 5,609,562; and 5,385,572, the teachings of all of which are expressly incorporated herein by reference.
A further related surgical instrument is disclosed in U.S. Pat. No. 6,007,481. Essentially, such device comprises an elongated sheath having a cone-shaped distal window. Such sheath has a screw-shaped blade to cut through tissue, while a scope can also be inserted to view the tissue penetration through the distal window. A second scope is proposed to also be able to get to the distal tip off the conical window for viewing distal to the point of the conical tip. This patent teaches the use of a fiberscope for visualization which implies a constant diameter scope with poor image quality due to the small number of pixels. More importantly viewing is limited by the inability of the viewing scope to get past the distal tip of the cutting sheath.
Furthermore all of the above mentioned prior art devices need a large incision and are taught to be used with a constant Outside Diameter (OD) viewing scope.
Commercial Optical Trocars:
Some commercially available laparoscopic entry systems with optical aid include the VersaStep (by Covidien Ltd.) with a trocar that can support a laparoscope going through a pre-inserted smaller but expandable needle. The first entry of the small needle is still blind, and the final wound made by the larger trocar still implies a larger trauma through the abdominal wall. Furthermore visualization is not possible during entry or insufflation.
The Visiport (by Covidien Ltd.) consists of a hollowed trocar with a wire blade that can cut through tissue, and a spherical crystal end. It can support a zero degree forward viewing laparoscope for inspection of entry through tissue.
The EndoTip trocarless visual cannula entry system by Karl Storz GmbH utilizes a spiral radial force version of the above mention optical large trocars that reduces the amount of axial force needed to get through the tissue while allowing for a laparoscope to monitor entry through the abdominal wall. But it is still a large device that requires an equally large incision, including a large and expensive laparoscope.
For the prior art described earlier as well as the commercial products introduced above, despite their ability to optically display tissue layers on the monitor during entry, these instruments retain either the conventional push through trocar and cannula insertion dynamics where entry is achieved by palming the entry device and applying considerable perpendicular axial pressure force (because of their very large diameter >5 mm-15 mm diameter cutting needles—or even larger), towards the abdominal cavity or radial force for the EndoTip, to propel the device into the peritoneum. Furthermore all these devices require a large incision of 10 m-15 mm for the large trocar to get through the tissue and support large instrument entry. They penetrate tissue by tearing it, not puncturing it like a needle. Also the conventional visualization laparoscopes they use are constant in their outside diameter all along their length and large in diameter as well, >5 mm. Also the ones that require insufflation prior to their use, by design, are part of a second entry into the abdomen, and assume a prior blind entry has already been made.
Because of all of the above, such commercial devices would never be possible to accommodate outpatient, minimally invasive laparoscopies that may not require anesthesia. Not all of the above mentioned commercial products can accommodate pneumoperitoneum with the proposed laparoscope in place. The ones that can, have even larger diameter cutting cannula to leave enough annular space between the laparoscope OD and the inside diameter (ID) of the sheath it goes through. Their use depends on another puncture that has been made prior to their use for insufflation. Descriptive pictures and more details for such commercial instruments can also be found at laparoscopy.net/safe/safe3.htm.
Commercial Optical Veress Needle:
Better optics, miniaturization and advances in instrumentation allowed improvements in rigid and flexible narrow caliber micro-laparoscopes that require very small diameter entry ports with potential advantages. Some have introduced a visual entry system that requires a 1.2 mm semi-rigid zero degree micro-laparoscope that fits into a modified Veress type needle (Optical Veress Entry System; Karl Storz Endoscop GmbH, Tuttlingen, Germany). One major advantage of such system is that it may be inserted in the umbilicus or the left upper quadrant, and subsequent ancillary ports can be inserted under direct vision (“Optical Veress as an entry technique.” Gynaecol Endosc, 8:379-92, (1999)). This reusable system, like other optical entry instruments, is safest when applied after insufflation (“Recent advances in endoscopic entry techniques,” Rev. Gynecological Practice, 1, 60-69, (2001)). The system offers poor optics (being a fiberoptic scope). In addition, these expensive and very delicate instruments fracture easily given their narrow diameter and top-heavy camera end. They can be applied through the left upper quadrant in high-risk cases, during diagnostic conscious pain mapping and in critical care or outpatient diagnostic units (“The role of microlaparoscopy in the diagnosis of peritoneal and visceral adhesions and in the prevention of bowel injury associated with blind trocar insertion,” Audebert A J. Fertil Steril; 73:631-5, (2000)).
The poor quality of the optics in these mini laparoscopes, and their fragility (due to the coherent imaging fiber bundle construct; fiberscope) render them impractical to use. Furthermore no teachings are made of a tapered scope design that can accommodate a high-resolution digital sensor while it can still allow insufflation through a standard small Veress needle.
Also U.S. Pat. No. 4,869,717 describes a Veress needle that can accommodate an instrument. They propose a complicated Veress needle modification that can receive an instrument (including an imaging scope, although they do not directly mention that) by adding an outer sheath that is integrated to the outside of the needle shaft of a practically standard Veress needle. Once insertion and pneumoperitoneum is achieved the needle along with the inner insufflation port can be removed while the outer sheath can remain in place to be used to pass through other instruments. This requires an extended design change to a Veress needle, which in addition makes a larger puncture than the underline Veress needle that they modified (since the sheath that remains is exterior to the Veress needle). Much different than what we propose to do. In addition, from the architecture of their modality, insufflation must be initiated first and then one can insert an instrument. Furthermore they are no teachings in this patent about a tapered visualization scope.
There is thus a substantial need in the art for a system and method that can enable a surgeon to selectively enter a body cavity, vessel, or organ, for purposes of performing endoscopic procedures whereby the surgeon is provided with direct visualization during entry such that tissue separation can be visualized and organ and tissue damage can be avoided (i.e., the surgeon can see the tissue prior to dissecting the same), while at the same time, the instrument penetrating the tissue has a small overall OD (less than 3.1 mm and preferably less than 2.1 mm, like a small size standard Veress needle) that requires a small incision of less than 2 mm for its entry, and can support abdomen insufflation while at the same time provide images and live video of the area distal to the puncture instrument; and yet despite its small size, the visualization scope can produce high quality images. Finally because of the small diameter of the penetrating tool and necessary incision size, outpatient microlaparoscopes can also be supported.